And I'm Renee Montagne. U.S. Customs and Border Protection has come under intense scrutiny this year for shootings by its agents along the Southwest border. Unarmed people have died after throwing rocks at border agents who shot back. The agency's investigations of many of these incidents have been kept from the public. Now word of a shakeup - the CBP has replaced its longtime chief of internal affairs, and it's bringing in an FBI agent to take a closer look at the use of force and border corruption. With us to talk about those charges is NPR justice correspondent Carrie Johnson. Good morning.

CARRIE JOHNSON, BYLINE: Good morning, Renee.

MONTAGNE: Tell us about this head of Internal Affairs and just exactly why he's been fired.

JOHNSON: His name is James Tomsheck. He'd been head of internal affairs since 2006 and before that, a longtime Secret Service agent. His ouster is being characterized as a reassignment. He'd been scheduled to testify at a Senate hearing Monday, Renee, but instead a deputy showed up, which was a clue something was going on.

And as for the reason why, Gil Kerlikowske, who's the new leader of Customs and Border Protection, says he's committed to integrity and transparency and investigations. He says he's asked the FBI for help in fulfilling that mission, and the FBI have sent over Mark Morgan. Mark Morgan once ran the FBI office in El Paso, Texas, along the border. And he now is the number two in the inspections unit at headquarters at the FBI, which are pretty perfect credentials for this new job.

MONTAGNE: Remind us of the broader concerns surrounding U.S. Customs and Border Protection.

JOHNSON: We at NPR have been hearing complaints since January about lackluster performance in investigations, little evidence of investigative activity and little follow-up in many of these cases where Customs and Border agents have shot and injured people along the border. And there's some evidence to back that up, Renee.

A law enforcement research group recommended that Customs and Border Protection change its use of force policy. Instead, the agency's initial response was to suppress that report for weeks. And MORNING EDITION in recent weeks has talked with family members whose relatives died. They've never heard anything back from CBP, in some cases for three years or more. And maybe the straw that broke the camel’s back here, an immigrant advocacy group found 800 some cases of abuse - alleged abuse by CBP agents along the border, Renee. There are materials they released last month - indicate only 13 of those agents were disciplined.

JOHNSON: Yeah, it's hard to overstate the importance of Customs and Border Protection to the immigration issues that are at the center of what the White House wants to accomplish at the end of President Obama's second term. And what many, many lawmakers believe is necessary in order to achieve re-election and even broader policy aims. Second, Renee, one other reason for this is that there are new people in charge at the Department of Homeland Security now, which oversees Customs and Border Protection. Jeh Johnson, the new secretary, his deputy, Ali Mayorkas, are used to being in the fire, and they don't like some of this bad press. And they also have a Justice Department background. So they may not appreciate the way some of these investigations were handled back in the day.